请教：DELPHI中如何存取ORACLE的CLOB或BLOB字段？

Question

需要调用oracle中的dbms_lob包吧

Answer 1

http://expert.csdn.net/Expert/topic/1373/1373219.xml?temp=.5225946
http://expert.csdn.net/Expert/topic/934/934551.xml?temp=.7429468
http://expert.csdn.net/Expert/topic/708/708732.xml?temp=.1524927
http://expert.csdn.net/Expert/topic/637/637661.xml?temp=.4878809
这都是我的收藏.
其实你要是搜索一下会有很多类似问题的.

Answer 2

在PB中有一个：SELECTBLOB查询语句，我想在DELPHI中也应该有一个类似的东西才对。当然如果太大，就需要调用：DBMS_LOB包的相关功能了。

Answer 3

blob资料：
http://otn.oracle.com/pls/tahiti/tahiti.drilldown?re=&word=blob&book=a85397&preference=CLOB:
select to_clob(col_name) from table_name;
blob:
select dbms_lob.substr(col_name) from table_name;

Answer 4

放一个dbimage控件，一个OpenPictureDialog，一个装载按钮；uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ToolWin, ComCtrls, DBCtrls, Buttons, DB, ExtDlgs, DBClient;type
  TFrm_YGXX_TPWH = class(TForm)
    ToolBar1: TToolBar;
    SpeedButton_ZZ: TSpeedButton;
    SpeedButton_BZ: TSpeedButton;
    SpeedButton_TC: TSpeedButton;
    OpenPictureDialog: TOpenPictureDialog;
    DBImage_TP: TDBImage;
    DS_YGTP: TDataSource;
    procedure SpeedButton_ZZClick(Sender: TObject);
    procedure SpeedButton_BZClick(Sender: TObject);
    procedure SpeedButton_TCClick(Sender: TObject);
    procedure DBImage_TPKeyPress(Sender: TObject; var Key: Char);
    procedure FormShow(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  public
    { Public declarations }
    VU_YGBH: string;
  end;var
  Frm_YGXX_TPWH: TFrm_YGXX_TPWH;implementationuses U_DM_QYJGSJ;{$R *.DFM}procedure TFrm_YGXX_TPWH.SpeedButton_BZClick(Sender: TObject);
begin
 if not DM_QYJGSJ.CDS_YGTP.IsEmpty then
  BEGIN
    DM_QYJGSJ.CDS_YGXXKL.Close;
    DM_QYJGSJ.CDS_YGXXKL.CommandText:='DELETE FROM T_YGTP WHERE YGID='''+VU_YGBH+'''';
    DM_QYJGSJ.CDS_YGXXKL.Execute;
  END;
  DM_QYJGSJ.CDS_YGTP.Refresh;
    //Frm_wlxxwh.CDS_WLTP.RemoteServer.Connected:=TRUE;
   // Frm_wlxxwh.CDS_WLTP.Delete;
end;procedure TFrm_YGXX_TPWH.SpeedButton_ZZClick(Sender: TObject);
var
  f: file of byte;
  VL_size: longint;
begin
  if OpenPictureDialog.Execute then
  begin
    AssignFile(f, OpenPictureDialog.FileName);
    Reset(f);
    VL_size := FileSize(f);
    CloseFile(f);
//    if VL_Size > 2097152 then
    if VL_Size > 2048000 then
    begin
      Application.MessageBox('ÎļþÌ«´ó,²»Äܱ£´æ!', 'ÌáʾÐÅÏ¢', mb_OK or mb_ICONINFORMATION);
      Exit;
    end;
    if not (DM_QYJGSJ.CDS_YGTP.State in [dsEdit, dsInsert]) then
      //Frm_wlxxwh.CDS_WLTP.Open;
      DM_QYJGSJ.CDS_YGTP.Edit;
    DBImage_tp.Picture.LoadFromFile(OpenPictureDialog.FileName);
  end;
end;procedure TFrm_YGXX_TPWH.SpeedButton_TCClick(Sender: TObject);
begin
  if DM_QYJGSJ.CDS_YGTP.State in [dsEdit, dsInsert] then
  begin
    DM_QYJGSJ.CDS_YGTP.FieldByName('YGID').asstring := VU_YGBH;
    DM_QYJGSJ.CDS_YGTP.Post;
    DM_QYJGSJ.CDS_YGTP.ApplyUpdates(0);
  end;
  Close;
  //Frm_WLXXWH_TPWH.Free;
  //Frm_WLXXWH_TPWH := nil;
end;procedure TFrm_YGXX_TPWH.DBImage_TPKeyPress(Sender: TObject;
  var Key: Char);
begin
  //Óû§Ñ¡ÔñÈ·¶¨£¬Ôò±£´æ£¬°´esc·ÅÆúÐÝ´æ
  if (Key = #13) then
  begin
    if DM_QYJGSJ.CDS_YGTP.State in [dsEdit, dsInsert] then
      DM_QYJGSJ.CDS_YGTP.Post;
  end
  else if (Key = #27) then
  begin
    if DM_QYJGSJ.CDS_YGTP.State in [dsEdit, dsInsert] then
      DM_QYJGSJ.CDS_YGTP.Delete;
  end;
end;
procedure TFrm_YGXX_TPWH.FormShow(Sender: TObject);
begin
  DM_QYJGSJ.CDS_YGTP.Close;
  DM_QYJGSJ.CDS_YGTP.Params[0].ASSTRING := VU_YGBH;
  DM_QYJGSJ.CDS_YGTP.Open;
 IF  DM_QYJGSJ.CDS_YGTP.RecordCount>0 THEN
{  if Frm_wlxxwh.CDS_WLTP.FieldByName('wlbh').asstring <> '' then
    Frm_wlxxwh.CDS_WLTP.Edit
  else
    Frm_wlxxwh.CDS_WLTP.Insert;
  Frm_wlxxwh.CDS_WLTP.FieldByName('wlbh').asstring := VU_WLBH;}
end;procedure TFrm_YGXX_TPWH.FormClose(Sender: TObject;
  var Action: TCloseAction);
begin
  if DM_QYJGSJ.CDS_YGTP.State in [dsEdit, dsInsert] then
  begin
    DM_QYJGSJ.CDS_YGTP.FieldByName('YGID').asstring := VU_YGBH;
    DM_QYJGSJ.CDS_YGTP.Post;
    DM_QYJGSJ.CDS_YGTP.ApplyUpdates(-1);
  end;
end;end.